Apparatus for identifying fluids passing through a formation testing tool



Jan. 5, 1960 K. H. MINER APPARATUS FOR IOENTTRYTNO FLUTOs PASSING THROUGH A FORMATION TESTING TOOL Filed Jani s, 195e 3 Sheets-Sheet 1 Jan. 5, 1960 K. H.'M|NER APPARATUS FOR IDENTIFYING F' LUIDS PASSING THROUGH A FORMATION TESTING TOOL s sheets-snm 2 Filed Jan. 3, 1956 Jan. 5, 1960 K. H. MINER 2,920,267 APPARATUS FOR IDENTIFYING FLUIDS PASSING THROUGH A FORMATION TESTING TOOL Filed Jan. 3, 1956 3 Sheets-Sheet 5 X k 50 k Q U 0 e zl/ Ic a c' 9 k. 1 -gm som; wm g aaai wps/0N CoA/Mins IME 5025 glo/.5 fz/.wp /za/ mgm] ILV/D Q i #SM Ml) .6E/74 A. fil/N52 INVENToR.

United States Patent a APPARATUS FOR nJENTIFYns'G FLUIDs PAsvsn'sG THROUGH A FORMATION TESTING TOOL Keith H. Miner, Newport Beach, Calif., assgnoi", by mesue assignments, to Dresser Industries, Inc., Dallas, Tex., a corporation of Delaware Application January s, 1956, serial Na. 551,093 15 claims. (CI. 324i This invention relates in general to well testing and more particularly to a system for determining the character and quantity of uids initially produced from a given zone in an earth borehole.

In the drilling or reworking of wells, particularly oil and gas wells, it is desirable to determine, at anychosen depth in the well borehole, and prior to permanent completion thereof, the kind of fluid which the penetrated formation at such depth is capable of producing. A

Patented Jam.v s, 1960t Ice I an improved system for well borehole production testing;

It is another object of this invention to provide an improved system for identifying the different fluids entering a well borehole production testing tool.

It is still another object to furnish a system for more accurately determining the quantities of the several different kinds of lluids entering a borehole and a well borehole production testing tool.

It is a still further object of thisinvention to furnish an improved well borehole production testing tool ca i pable of furnishingmore information relative to the idenable portion thereof, a packer device for packing oi number of variations of So-called formation testing or drill stem testing systems have been heretofore employed for the purpose of Obtaining such information regarding the potential production possibilities of drilled earth formations. These systems employ for the most part the now well known method usually comprising the lowering into the well borehole of a string of drill pipe, tubing, or the like tubular member carrying adjacent the lowered end thereof a suitable packer device adapted to seal olf the annular space between such tubular member and a selected portion of surrounding borehole wall, thereby to isolate a chosen portion of the earth borehole below such packer and thereby to place it in communication with the lower end of such tubular member. A valve device manipulatable from the top of the well borehole is usually associated with lthe packer or lower portion of the tubular member, which valve can be initially closed to permit the tubular member to be run into the borehole empty or at least at a pressure substantially lower than that of the surrounding fluid in the well borehole.

' Upon the setting of the packer followed by the opening of such valve, uid from the borehole below the packer may then enter the lower end of the tubular member, followed by fluid from the surrounding earth formations, and such fluid may then rise inthe tubular member either to a level where pressure equilibrium is established between the uid column in the tubular member and that of the formations surrounding the earth borehole below the packer, or if the formation pressure is sufiiciently high, such pressure equilibrium may not be established and continuous ow out through the tubular member may result.

In either event, it is desirable to be able to determine the sequence of entrance and the character and approximate amounts of the different kinds of fluid thus initially entering the tubular member of the testing tool.

Since, when the testing device valve is opened, the fluid may enter the testing tool with considerable velocity which tends to mix the different kinds of entering fluid, and also in event subsequent sampling of the recovered fluid sample is attempted by withdrawing the tubular member and catching samples therefrom as the joints of such member are broken, as has been the usual practice heretofore, 'much difculty is encountered in obtaining accurate oruseful information as to the aforesaid different kinds and quantities of fluid entering the testing tool. n

It is, therefore, au object of this invention to provide the annular space between such member and the surrounding borehole wall, thus to isolate a portion of the borehole adjacent .the packer from other portions of the borehole, and a valve device in said container or tubular member adapted to be initially closed while said memberV and packer are being lowered into place in said borehole to exclude entrance of fluid into said member, and capable of being opened to permit entrance of uid from the said isolated portion of said borehole into the said member, said packer and valve being manipulatable from the .top of the borehole, and means associated with said member, valve and packer for indicating, or making a record correlated with time, of the measure of the resistivities or conductivities of such of the several kinds of fluid as may ow into said tubular member following the opening of said valve. n

These and other objects, advantages and features of novelty of .the invention will be evident hereinafter.

In the accompanying drawing wherein a preferred; embodiment and best mode contemplated for accomplishing this invention is illustrated:

Figure 1 is a longitudinal sectional view of the general assembly of the apparatus in position within a typical Well borehole;

Figure 2 is a fragmentary longitudinal sectional View in detail of a portion of the apparatus taken on line 2--2 of Figure 1; v

Figure 3 is a schematic diagram of the electrical crcuit of the apparatus of Figure 2;

Figure 4 is a longitudinal sectional View of an alternative form of the apparatus of Figure 1;

Figure 5 is an illustration of one type ofgraphical record which may be made by the apparatus of the invention. I

Referring rst primarily to Figure 1, a typical well bore hole is shown at 10 having an upper section 11 of relatively large diameter and having a lower section 12 of a reduced diameter relative to the aforesaid upper section. At the juncture of the upper section 11 and the lower section 12 of the well borehole is formed a tapered seat 13 into which and against which a tapered packing element 14 of a packer device, hereinafter more fully described, is forced to form a uid seal or packolf therewith, thereby to isolate the upper section 11 from the lower section 12 of the well borehole.

The testing apparatus assembly, as shown in Figure 1 is lowered into the well bore upon a drill stem, drill pipe, tubing or the like hollow or tubular member i6 and comprises, in addition to the beforementioned tubular member, a valve 19 which has an upper rotatable valve ele ment 18 and a lower stationary valve element 20, a tubua;

theborehole;asf.illustrated;in Figure 1.. 'Fhenuppenvalvev element 18 andthe. lowerrvalve elementlhof-'the valve.

19" are rotatable relativetoeach other about the longitudinal axis of the toolto. the limited extent permitted by.- the.slot.26 inlthe valve element 13; 28 in the valve element 29 as best showninFigure 4. The valve elements.18aud 20rare rotatably secured together, end to end, by means. of. the longitudinal shaft 29 integral with.

andfextendingcoaxially. up from the lower valve. element 201fthrough a central .bore in the` upper valve element 1S, saidishaft^29 being pro-videdfwith.a-threaded upperend carrying a retainer nut 30.

The upper valve element 1S and the lower valve elementZ in the valve 19 are each provided with a pair of internal, longitudinally extending passages; 31 and 32 respectively, which in the one extreme rotational position of the` valve elements .relative to one another permitted bythe beforementioned slot and pin 26, 2S as shownin Figure 1, are in registry with each other, thereby completing a pair of fluid passages through thevalve 19 from the lower end of the tubular member 16 to the central passage 33 of the mandrel 21, which in turn makes connection with the interior of the upper end portion of the perforated pipe 24. in the extreme opposite position of the upper valve element 18 relative to thev lower valve element 29 of the valve 19 permitted bythe slotand pin Z6, 2S the valve passages 31 and 32 are out of registry with each other, thus closing off communication between the. lower portion of the testing tool through mandrel passage 33 from that of the upper portion of the tool leading into the tubular member 16.

Thus it will be apparent that after the testing 1toolis lowered into rthe borehole upon the driil stem or tubular member 16 and the packing 14 is forced into sealing and rictional engagement with the seat 13, the lower valve element Ziiwiil thereby be heldstationary and the valve 19 may then be opened or closed as desired, by rotation of the upper element 18 of the valve by rotary manipulation of the tubular member 16 from the topk of the well borehole.

Adjacent. the upper end of the'beforedescribedtesting tool .and within the tubular member 16, as showninFigure 1, is located a iluid tight pressure resistant housing 35V 'supported centrally within the tubular mem-ber 6 by means of a plurality of radially extending web members 36 and 37 attached to the upper and lower heads respectively of the housing SSand Vwhich make supporting engagement with the inside surface ofthe bore of tubular member 36. The constructionof the containeriASS-and the contents thereofzare morefully described hereinafter in connection with Figure l2..

Referring now primarily to 4Figure 2, the housing 35 'is provided, on at least a portion of the exterior surface thereof, with a coating or covering 38 of a suitable' electrical insulating material such as rubber, neoprene, Bakelite or the like rubber-like or plastic material. Uponthe exterior surface of insulating covering 43 is carried. a pair of longitudinally spaced-apart annular electrodes 39' and 4G. The annular' electrodes 39and 40 are electrically connected by means of conductors 41 and 42 respectively which pass through insulating bushings 47 and 48 located inthe wall of the housing 35 to measuring apparatus con-- tained within the housing hereinafter more fully described.' A portion of the interior surface of the tubular memberV 16, at a location opposite the aforementioned coating 38, isrpreferably, although not necessarily, coveredwith an insulating coating 44 which'may be composed of materialwhich is the same as, or similar to, that of the beforev mentioned coating 37j Contained within the housing 35 are resistance-measuring means comprising-an ammeter 4S, connected in series through conductor 43 with a suitable current supply means 46 which series circuit is in turn connected, by way of conductors 41 and 42, across electrodes 39 and 40, as illustrated diagrammatically in Figure 3. The current supply means 46 may comprise an electric battery to produce arsuitable direct current, or preferably` it` may cornprise aV source of alternating current includingv a battery and a suitable inverter or switching means to produce an alternating current, or a periodically reversed directed current of suitable frequency to be applied acrossy the electrodes 39 and 40.

The meter 45 is providedwith a pen 49which rests upon and is adapted to draw a graphical record upon a moving chart 51 off'values representative of iluid resistivity or conductivity versus time as shown at 49. The chart 51 is adapted to be driven at a predetermined uniform rate in the direction indicated. by the arrow, by means of a clock drive mechanismSZor other suitablemeans for this purpose, as. is well knownin the art.

While the apparatus of .the invention has been hereinbefore described, by way of illustration, as beingv used in combination .with'atso-called rat-hole type drill stem formation tester in anopen well borehole, it is to. be under stood that the apparatus may also be adapted to make the; same. or similar tests in a cased borehole, andunder such condition asimilar. testing tool employing a sleeve-packer. or. a so-calledhook-walltype packer ora plurality of such.y packers maybe used. Such testing apparatus may also be combined with a gun perforater device in a manner. which is thesame as ori similar to that illustrated inithe Spencer Patent No. 2,092,337, to pert'orate suchcasing prior to making such test.

While in Figure 1 the instrument housing 3S is shown` t0 be located within the tubular member 16 and above the valve 19, it may also be .located below the valve 19 and within theperforated pipe or strainer 24, as illustrated in Figure 4.

In operation of the beforedescribed lapparatus of this invention, the valve 19 is initially closed. The apparatus is then lowered down through the well borehole and through such fluid as is present therein until the packing element 14 is brought to rest upon the tapered seat 13 of. the formation and forced thereagainst by the weight of the tubular member 16 sufficient to seal olf the upper section 10 of the borehole from the lower section 12. By. thus maintaining the valve 19 closed .the fluid presentin the well will be prevented from entering the tubular member 16 and thus the tubular member 16 will be initially, maintained empty of uid.

. Idesired, however, a suitable quantity of fluid mayy be introduced into the tubular member 16, above valve 19, as'it is lowered into the well borehole to act as a cushion against the incoming fluid during the initial stage of the testing operation following the opening of the valve 19, as hereinafter more fully described.

When vthe testing apparatus has thus been loweredl into the well borehole in'readiness for testing, the valve 19V is then opened by turning the tubular. member 16y to the extent permitted by the slot and pin 26, 2S to bring the passages 31 and 32 in the valve elements 19 and 2t) respectively into registry and communication with each other as shown in Figure l. The fluid in the lower section of the borehole `12.surrounding theperforated. pipe 24 and also the uidfin the formation adjacent thereto being of relativelyhigh pressure with respectto the interior of the tubularmemberrl then flows inward through the perforated pipe 24 through the passage 33 ofthe mandrel 21 and thence up through valve passages 32'and 31V into' the interior of the tubularmember 16. As.` the fiuidthus entering the testing` tool continues-to flow-it passes upward through the annular space between the instrument housing 35 and the interior walls of thetubular member 16 until the fluid column in thcitubulr" reinber 16 has risen thereabove to a height where the pressure head thereof is in equilibrium with the pressure of the formation surrounding the lower section 12 of the borehole, or in case the formation pressure is sufliciently high, such iiuid column within the tubular member 16 may reach the top `of the well and flowing production of the well may thus be attained and maintained for a period of time.

As the uid thus permitted to enter the lower end of the tubular member 16 through the beforedescribed testing tool passes through the beforementioned annular space, surrounding the instrument housing 35, it comes in electrical contact with the annular electrodes 3-9 and 40. Current may thus be permitted to flow through such uid between the annular electrodes 39 and 40 and through conductors 41, 42 and 53, and through the meter 45, under the influence of the potential or current source 46. The deflection of the pen 48 of the meter 45 -Will thus be a measure of or a function of the resistance or conductivity of a certain volume of the fluid at any particular time flowing between the aforesaid annlar electrodes 39 and 40. As a result of the uniform movement of the chart 51 a graph 50 is drawn upon the moving chart 51 which, as before stated is a measure of or a function of the resistivity or conductivity, with respect to time, of the fluid passing in contact with the electrodes 39 and 40.

Referring now primarily to Figure 5, in which the graphical record 50 plotted by the apparatus of Figure 2 is'fshown in enlarged detail upon the chart 51, the time interval zero-a` corresponds to that during which the Y testing apparatus, having the arrangement shown in Figure 1, is lowered into the well borehole with the valve 19 closed. During this time interval, when employing the apparatusof Figure l, the conductivity of the fluid in the annular space surounding the electrodes 39 and 40 being for example air, is indicated as substantially zero.

During the interval of time a-b the valve is in the process of being opened by rotation of Ithe tubular member 16, and the time interval b--c represents that required for the entrance of the fluid contained in the borehole section 12 surrounding the perforated pipe 24 to pass upward through the testing tool and completely to fill thel annular space in the tubular member 16 surrounding the instrument housing 35.

The time interval c-d is that during which the relatively low resistivity borehole tiuid, which may be drilling mud, which had been entrapped in the lower sec tion of the borehole 12 below the packing element 14 and surrounding the perforated pipe 24 is being displaced upward into the tubular member 16 and is flowing through the annular space surrounding the instrument housing 35 in contact with the electrodes 39 and 40, and the resistivity measurement maintained during such period c-a' indicates the resistivity value of such borehole fluid.

' The time interval d-e indicates the effect of the conductivity measurement during the transition from flow of uid initially entrapped in the lower portion of the borehole surrounding the perforated pipe 24 to and in# elusive of fluid from the surrounding formation which wask present in such formation by reason of invasion or infiltration thereof from the borehole during drilling.

The time interval e-f represents the measure of the conductivity of the fluid flowing from the formation after substantially all of the invasion fluid has been dis- Y placed from the formations adjacent the point of test,

and flow of substantially uncontaminated connate iiuid from the surrounding formations has been established. In the case illustrated in Figure 5, since the conductivity of the connate liuid is indicated as being substantially lower than that of the borehole fluid and of the invasion uid, this may be taken, for example, as an indication of the production of a relatively low conductivity fluid such asvoil or gas during this time interval.

Upon completion ofthe foregoing steps in the testing operation the valve 19 is closed by rotation of the valve element 18, the packer released and the tubular member 16, together with the testing tool, withdrawn from the borehole. The time interval f-g represents the time during which such withdrawal from the borehole is effected and during which the indicated conductivity of the rtained uid obviously remains constant.

With a known fluid column height established within the tubular member 16 upon the completion of the test, or in the case of continuous flow of known rate being established, then from the known time intervals of flow of the different kinds of fluid through the testing tool as indicated by the record of the type illustrated in Figure 5, the relative quantities of the various kinds of such uid may be estimated. y

Operation with the apparatus of Figure 4 will result in a record similar to that shown in Figure 5 except that because the instrument housing 35 and particularly the electrodes 39 and 40 are located below the valve 19 the uid in the borehole can come into contact with the electrodes during the initial lowering of the apparatus into the well bore and before the valve 19 is opened. Therefore, in such casing the graph may show an initial reading which represents the conductivity of such fluid present in the well bore during the initial time interval zero-a. Also during withdrawal of the apparatus from the well bore during interval f-g the electrodes may again be brought into contact with borehole fluid and the graph 50 may show an increase in conductivity during that interval. Otherwise the graph 50 will be of the same character whether made by the apparatus arrangement of Figure l or Figure 4. An important feature of the present invention resides in being able to obtain an indication of the character and quantity of the different kinds of fluid as they enter the testing tool, regardless of the extent of subsequent intermixing of the different kinds of such fluids resulting from turbulence of flow which may occur within the drill stem or tubular member above the testing tool as the entering uid rises therein. It also has the advantage over systems hereinbefore employed where the kinds and quantities of fluids recovered by the testing tool had to be determined by breaking the joints of the tubular member as it is withdrawn from the well and catching, as best as possible, the fluid discharged at such joints.

The arrangement of the apparatus illustrated in Figure 4y may be advantageous in some cases in permitting measurement of the resistivity of the various fluids enter ing the testing tool prior to passing through the tool and prior to such initial turbulence and mixing as may occur therein. The undesirable effect of mixing of the liuids will thus be minimized.

While one arrangement of electrodes adapted to make electrical contact with iiuid entering the testing device is illustrated by Way of example in Figures 2 and 3, other arrangements may be employed, Within the skill of the art, to insure proper measurement of the desired electrical characteristics of such flowing uids.

It is to be understood that the foregoing is illustrative only and that the invention is not to be limited thereby, but includes all modifications thereof within the scope of the invention as defined in the appended claims.

What is claimed is:

1. A method of testing the production of a well comprising: lowering into the bore of the well to be tested a tubular member initially closed against entrance thereinto of fluid from said well bore; effecting a packol between said tubular member and a portion of the wall of 'the well bore at a selected location within the well bore wall to isolate a portion of said well boreV from other portions thereof; opening the said tubular member to allow fluid to enter said tubular member from the thus isolated portion of said Well bore Wall; and making a measure during entrance, indicative of the resistivity at a given 7 section thereof of the entire stream of fluids thus per.- mitted to enter said tubular member.

2. A method of testing Vthe production of a well cornprising: lowering into the bore of the Well to be tested a tubular member initially closed against entrance thereinto of uid from said well bore; effecting a packoff between said tubular member and a portion of the wall of the well bore at a selected location within the well bore to isolate a portion of said well bore from other portions thereof; opening the said tubular member to allow uid to enter said tubular member from the thus isolated portion of said well bore; and making a measure with respect to time during entrance indicative of the resistivity at a fixed section thereof of the entire stream of fluids thus permitted to enter said tubular member.

3. A method for testing the production of a well comprising: lowering into the bore of the well'to beftested a tubular member initially closed against entrance thereinto of fluid in said well bore; eecting a packoff of the annular space between the said tubular member and the surrounding wall of the well bore at a selected point within said well bore to isolate a portion of said well bore from other portions thereof; opening the said tubular member to allow fluid to enter said tubular member from the thus isolated portion of said well bore; and making a measure at a fixed location therein indicative of the resistivity of the entire stream of said fluid thus permitted to enter said tubular member, said measure Abeingmade in correlation withtime during such entrance of said fluid into said tubular member.

4. A method for testing the production of a well comprising: lowering into the bore of the well to be tested a tubular member initially closed against entrance' thereinto of fluid in said well bore; effecting a packoif of the annular space between the said tubular member and the surrounding wall of the well borehole at a selectedpoint within said well bore to isolate a portion of saidwell bore from other portions thereof; opening the saidtubular member to allow uid to enter said tubular member from the thus isolated portion of said well bore; andat a location iixed with respect to said tubular member, making a measure indicative of the resistivity ofthe entire streaml of said uid passing said location assaid uid enters said tubular member, said measure being made in correlation with time during'such entrance of said fluid into said tubularmember.

5. A method for testing the production of a welltcomprising: lowering into the bore of the'well to be tested a tubular member initially closed adjacent the lower end thereof; effecting al packotf of the annular space between the said tubular member and the surrounding'wall ofthe well bore at a point adjacent thelower end portion of said tubular member; opening the said tubing tofallow uid to enter said tubular member from thewell-bore below the said packoff point; and at a location fixed with respect to said tubular member making a measure indicative of the resistivity of the mixture of all of said uid passing said location as saiduidventers said tubular member, said measure being made in correlation-with time during such entrance of such fluid into said tubular member.

6. Apparatus adapte-d to be lowered into a well bore for testing the production of a well comprising: a tubular member initially closed against entrance thereinto of fluid from such well bore; an imperforate tubular extension of said tubular member; means` for effecting a paclio between said tubular member and a portion of said well bore wall to isolate a portion of said welltb'ore wall from other portions thereof; means intermediate said tubular member and said tubularextensionzto open said tubular member into communication through saidtubular extension with the thus isolatedporti'onV of'said Awell bore; and means including eiectrodemeans Vlocatedm/itin'n said: imperforate tubular' extension to make: arn'easure of the resistivity at a fixedlocationLthereintoftheiwhole Si streamof uidsthus permitted to. enterandow through said. `imperforate tubular extension into said tubular member from said isolated portion.

7. Apparatus adapted to be lowered into a well bore for testing the production of a well comprising: aftubular member initially closed against entrance thereinto of uid from such Well bore; an imperforate extension of said tubular member; means for etfecting a packoff between said tubular member and a portion of said well bore wall to isolate a portion of said well bore wail from other portions thereof; means intermediate said tubular member and said imperforate extension to open said tubular member into communication through said imperforate extension; with the thus isolated portion of said well bore; and means including electrode means located within said imperforate extension for recording in correlation withtime a measure of the resistivity at a fixed location therein of the whole stream of fluids thus permittedk to enter saidl tubular member from said isolated portion.

8; Apparatus adapted to be'lowered into awell bore for testing the production of a well comprising: aitubular member initially closed against entrance thereinto'of, fluidfrom such well bore, said tubular member havingV an imperforate extension; packer means for effecting a packoff between said tubular member and a portion of saidwell bore -to isolate a portionof said-.well bore from other portions thereof; means to open said tubular mem ber into communication through said. imperforate extension with the thus isolated portion of said well bore;.and meanslocated adjacent said packer means Wholly within said imperforate extension to makea measure of the resistivity at a xed location therein of the whole stream of uids thus permitted to enter said tubular member. from said isolated portion.

9. Apparatus'adapted to be lowerediinto a wellbore. for testing the production or a well comprising-z ay tubular member initially closed against entrance thereinto of uidfrom such well bore, said tubular memberl having an imperforate extension; packer meansfor effecting a. packoft' of the annular space between said tubular member and the surrounding wall of the well bore ata selected location within said well bore to isolate a portion of said well bore from other portions thereof; meansfr opening said tubular member into communicationwith such isolated portion of the well bore through said imperforate extension; and means for making a measure of the resistivity at a fixed location within-said imperforate extension of the whole stream of fluid thus. permitted to enter said tubular member. through said imperforate extension from said isolated portion` l0. Apparatus adapted to be lowered into atwell bore for testing the production of a well comprisingz. a tubular member initially closed against entrance:thereinto of fluid from such well bore; packer meansfor. effecting a packoff of the annular space between saidtubular member and the surrounding wall of the well boreatv a selected location with-in said well bore to isolate. aportion of' said well bore from other portions thereof; opening means for opening said tubular member. into. communication with such isolated portion of the Ywell bore; and means located adjacent said packer abovesaid opening means for recording in correlation withtirne a measure of the resistivity at said location of thev wholestream of all of the huid thus permitted to enter saidy tubular member from said isolated portion.

ll. Apparatus adapted to be lowered into a well bore for testingthe production of a well comprising: atubular member initially closed against entranceh thereinto of fluid fromV such well bore; packer means. for` eifectrng a packoffiof the annular space between said. tubular. memberv and thesurrounding wall of the Well bore aty a selected location within said well bore to isolateA a. portion of=. said well borefrom other portions thereof; valve means carried by' said tubular member adjacent said packer means,- actnatable for openingA said tubular member into communication and closing said tubular member from communication with such isolated portion of the well bore; and electrode means located within said tubular member adjacent said packer means for recording in correlation with time a measure of the electrical conductivity of all of the uid thus permitted to enter said tubular member through said Valve means from said isolated portion.

12. Apparatus adapted to be lowered into a well bore for testing fluid therein comprising: a hollow member initially closed against entrance thereinto of uid from such well bore; valve means carried by said hollow member and actuatable for opening said hollow member into communication with liuid in said well bore; and means contained within said hollow member above said valve means for making a measure of the resistivity of all of the uids entering said hollow member through said valve means.

13. Apparatus adapted to be lowered into a well bore comprising: aA tubular member initially closed against entrance thereinto of fluid from such well bore; valve means carried by said tubular member and actuatable for opening said tubular member into communication with fluid in said well bore; and means including electrodes contained within said tubular member adjacent said valve means for making a measure of the resistivity of all of the fluids entering said tubular member through said valve means.

14. Apparatus adapted to be lowered into a well bore for testing fluid therein comprising: a tubular member initially closed against entrance thereinto of fluid from such well bore; valve means carried by said tubular member and actuatable while said tubular member is located within such well bore for opening said tubular member into communication with fluid in said well bore; and means contained within said tubular member adjacent said valve means for making a measure of the resistivity of all of the iluids entering said tubular member through said valve means.

15. Apparatus adapted to be lowered into a well bore for testing fluid therein comprising: a hollow member initially closed against entrance thereinto of uid from such well bore; an imperforate extension of said hollow member; valve means locatedbetween said hollow member and said imperforate extension and actuatable for opening said hollow member into communication through said imperforate extension with liuid in said well bore; means contained within said imperforate extension below said valve means for making a measure of the resistivity of all of the uids entering said hollow member through said extension and said valve means.

References Cited in the le of this patent UNITED STATES PATENTS 2,248,982 Gillbergh July 15, 1941 2,295,738 Gillbergh Sept. 15, 1942 2,300,206 Clark Oct. 27, 1942 2,364,159 Muly Dec. 5, 1944 2,377,501 Kinley June 5, 1945 2,729,784 Fearon Jan. 3, 1956 UNITED STATES PATENT O-F FICE v CERTIFICATE OF CORRECTION Patent No 2,920,267 January 5, 1960 Keith Htj Miner It ie hereby Certified that errer appears in Jthe printed epeeifieetien of the above numbered patent requiring correction and that the said Letters Patent should readas corrected below.

Column 4v line 62,l for l"19" read 18 --5 column 4line 23Y for "casing" read case ma; line 'Zlz before "to" strike out "wallffg same line T11 after "Wellbore" insert Wall Signed and sealed this 27th dayhof September 1960.

(SEAL) Attest:

KARL H. AXLINE ROBERT C. WATSON Attesting Offcer Commissioner of Patents 

